Project finance risk evaluation of the Electric power industry of Serbia

From the aspect of the development of a country, the energy sector represents a domain of strategic interest. Generation and use of energy resources most often belongs to the public sector, and are most often under the influence of the government in most countries. This paper analyzes the risks that are characteristic to the business of the public enterprise, Electric Power Industry of Serbia (EPS). EPS has started its restructuring and is adjusting to changes and challenges imposed by the launched reforms in the energy sector. However, due to certain limitations, it is still not possible to implement its complete restructuring and modernization. The paper aims to point at the risks a potential strategic partner faces. The risks have been identified as commercial, financial and political, classification immanent for project finance, and their evaluation was done using Failure Mode and Effects Analysis (FMEA). Risk analysis was performed based on current conditions for two potential scenarios that predict different types of changes in the analyzed period. The results of the analysis show that the potential strategic partner should pay special attention to price risks, estimation, investments, project activity neglect, quasi-risks and debt collection.     

Fast evaluation of dynamic changes of electric power systems frequency during primary control

The paper presents the development of a simple method for the fast and sufficiently accurate assessment of dynamic changes of power systems frequency during the time period of primary control. Also, this model gives corresponding values of the total mechanical power of synchronous generators, during the some period. The development of a proposed low-order system frequency response model is based on the main assumption of uniform movement of generators, which enables representation of the power system through an equivalent controlled synchronous machine. The characteristics of the developed method were determined on an example of a real electric power system and a comparison was made with the results of a stricter approach.     

Strategies defined for the development of applications using Multilayer Perceptrons: A survey

Abstract: The success in developing an application employing the Multilayer perceptron (MLP) as knowledge representation form is very dependent on the degree of complexity that the structure of the application's domain has. Different mathematical and/or statistical techniques have been developed to subtract the maximum amount of information of this type from an available sample of the operating space associated to the task of interest. In the context of MLP it has been used to decide on the form the different intervening parameters of the network and/or related learning algorithm (LA) should have. This paper provides an overview of the processes that have been defined to generate network applications using the MLP model, giving particular attention to those based on the dynamic creation of a network's architecture through the application of different techniques for subtracting information about the operating domain in which the training set is subsumed.     

Anticancer Potential of (Pentamethylcyclopentadienyl)chloridoiridium(III) Complexes Bearing κP and κP,κS‐Coordinated Ph2PCH2CH2CH2S(O)xPh (x=0–2) Ligands

Iridium(III) complexes of the type [Ir(η⁵‐C₅Me₅)Cl₂{Ph₂PCH₂CH₂CH₂S(O)_xPh‐κP}] (x=0–2; 1 – 3 ) and [Ir(η⁵‐C₅Me₅)Cl{Ph₂PCH₂CH₂CH₂S(O)_xPh‐κP,κS}][PF₆] (x=0–1; 4 and 5 ) with 3‐(diphenylphosphino)propyl phenyl sulfide, sulfoxide, and sulfone ligands Ph₂PCH₂CH₂CH₂S(O)_xPh were designed, synthesized, and characterized fully, including X‐ray diffraction analyses for complexes 3 and 4 . In vitro studies against human thyroid carcinoma (8505C), submandibular carcinoma (A253), breast adenocarcinoma (MCF‐7), colon adenocarcinoma (SW480), and melanoma (518A2) cell lines provided evidence for the high biological potential of the neutral and cationic iridium(III) complexes. Neutral iridium(III) complex 5 proved to be the most active, with IC₅₀ values up to about 0.1 μM , representing activities of up to one order of magnitude higher than cisplatin. Using 8505C cells, apoptosis was shown to be the main mechanism through which complex 5 exerts its tumoricidal action. The described iridium(III) complexes represent potential leads in the search for novel metal‐based anticancer agents.     

Nicotine prevents glutamate-induced proteolysis of the microtubule-associated protein MAP-2 and glutamate neurotoxicity in primary cultures of cerebellar neurons

The aim of this work was to assess whether nicotine prevents glutamate neurotoxicity in primary cultures of cerebellar neurons, to try to identify the receptor mediating the protective effect and to shed light on the step of the neurotoxic process which is prevented by nicotine. It is shown that nicotine prevents glutamate and NMDA neurotoxicity in primary cultures of cerebellar neurons. The protective effect of nicotine is not prevented by atropine, mecamylamine or dihydro-beta-erythroidine, but is slightly prevented by hexamethonium and completely prevented by tubocurarine and alpha-bungarotoxin, indicating that the protective effect is mediated by activation of alpha7 neuronal nicotinic receptors. Moreover, alpha-bungarotoxin potentiates glutamate neurotoxicity, suggesting a tonic prevention of glutamate neurotoxicity by basal activation of nicotinic receptors. Nicotine did not prevent glutamate-induced rise of free intracellular calcium nor depletion of ATP. Nicotine prevents glutamate-induced proteolysis of the microtubule-associated protein MAP-2 and disaggregation of the neuronal microtubular network. The possible mechanism responsible for this prevention is discussed.     

A more efficient design for reversible air–air heat pumps

In this article, a new design for reversible air–air heat pumps is proposed. This design is not based on the refrigerant changeover, as is proposed by ASHRAE, but rather is based on the inversion of the air flow on the ducts. Thanks to this modification it is possible to use any air–air refrigeration machine for air conditioning as a reversible heat pump.     

Chronic hyperammonemia impairs the glutamate-nitric oxide-cyclic GMP pathway in cerebellar neurons in culture and in the rat in vivo

The aim of this work was to assess whether ammonia concentrations similar to the increase found in the brain of hyperammonemic rats (100 microM), impair N-methyl-D-aspartate (NMDA) receptor-mediated signal transduction. We first measured glutamate neurotoxicity, which in these neurons is mediated by activation of NMDA receptors, as an initial parameter reflecting activation of NMDA receptor-mediated pathways. Long-term treatment of cultured neurons with ammonia prevents glutamate-induced neuronal death. The EC50 was 20 microM, and at 100 microM the protection was complete. The induction of the protective effect was not immediate, but took several hours. Treatment with 100 microM ammonia did not prevent a glutamate- or NMDA-induced rise of intracellular calcium. Ammonia impaired the glutamate-nitric oxide-cGMP (3',5'-cyclic guanosine monophosphate) pathway in a dose- and time-dependent manner. Glutamate-induced formation of cGMP was reduced by 42%, while activation of nitric oxide synthase was not affected. Ammonia reduced by 31% cGMP formation induced by S-nitroso-N-acetyl-penicillamine (SNAP), a NO-generating agent, confirming that the interference occurs at the level of guanylate cyclase activation by nitric oxide. To assess whether chronic moderate hyperammonemia in vivo also impairs the glutamate-nitric oxide-cGMP pathway, we determined by in vivo brain microdialysis in freely moving rats the formation of cGMP induced by NMDA. In hyperammonemic rats, the formation of cGMP induced by NMDA and SNAP was reduced by ca. 60 and 41%, respectively, indicating that chronic hyperammonemia in the animal in vivo also impairs the glutamate-nitric oxide-cGMP pathway. Impairment of this pathway can contribute to the neurological alterations found in hyperammonemia and hepatic encephalopathy.     

Prolog/Rex inference engine

Abstract: Prolog/Rex supports the construction of knowledge-based systems, allowing frames (Prolog/Rex concepts) and rules to be combined, and providing language level support for hypothetical reasoning and assumption-based truth maintenance (Prolog/Rex viewpoint mechanism). To increase run-time performance during rule execution, Prolog/Rex provides two complementary rule compilation techniques: the simple indexing scheme and the heavily modified Rete expansion method. To improve the efficiency of the inference engine, we built an agenda-based rule manager that uses priority mechanism and/or heuristics embedded in meta-rules to control the rule firing order. Forward- and backward-chaining can be combined within the same program.     

Adverse reactions to insulin

The prevalence of allergic reactions to insuline has decreased during the last few years. Probably this is due to the use of the newly-developed recombinant human insuline. At present, adverse reactions to insuline occur in 5-10% of patients on therapy with insuline. Adverse reactions may be local (more frequent) or systemic (rare). Insuline resistance consists in a different type of immunological reaction. Diagnosis of allergy to insuline is based on clinical history and cutaneous and serological tests. Treatment depends upon the severity of the reaction. When insuline is indispensable despite a previous allergic reaction, a desensitization protocol may be implemented.     

Pleural effusion in patients infected with the human immunodeficiency virus

In order to analyze the etiology, cytological and biochemical characteristics, and outcome of pleural disease in patients infected with HIV, the medical records of 86 HIV-positive patients with pleural effusion were reviewed. Controls were 106 HIV-negative patients with parapneumonic or tuberculous effusion. Most HIV-positive patients were intravenous drug abusers (95.3%). Pleural effusions in HIV-positive patients were caused by infections in 76 (89.4%) cases. Parapneumonic effusion was diagnosed in 59 patients and tuberculous pleuritis in 15 patients. Staphylococcus aureus was the most frequently isolated bacteria. Parameters for differentiating complicated cases of parapneumonic exudate from uncomplicated cases, such as pleural fluid pH < 7.20 (sensitivity 80% vs. 84.3%), pleural fluid glucose < 35 mg/dl (sensitivity 45% vs. 56.25%) pleural fluid LDH > 1600 UI/l (sensitivity 85% vs. 62.50%), showed similar sensitivity in HIV-positive and HIV-negative patients. Monocytes in pleural fluid were significantly decreased in tuberculous pleuritis in HIV-positive patients (506 +/- 425 vs. 1014 +/- 1196 monocytes/ml, p < 0.05). No significant differences were detected in the outcome of HIV-positive and HIV-negative patients with pleural disease. It can be concluded that the pleural effusion was of predominantly infectious etiology in HIV-positive patients from populations with a high prevalence of intravenous drug abuse. Neither the biochemical parameters in pleural fluid nor the outcome differed significantly between HIV-positive and HIV-negative patients.